Myocardial lead attachment system

ABSTRACT

The present invention is a myocardial lead attachment system for securing a distal end of a lead within a myocardium of a patient&#39;s heart. The system includes an anchor, a tether coupled to the anchor, and a delivery instrument for receiving and advancing the anchor through a tract in the heart from a proximal entrance site to a distal exit site in such a manner that the tether extends proximally from the anchor through the tract. The delivery instrument includes a needle having a distal tip and a nest. The nest is positioned proximal to the distal tip and is sized to receive the anchor. The delivery instrument further includes an ejection mechanism for ejecting the anchor from the nest.

CROSS REFERENCES

The present application claims the benefit of the following U.S.Provisional Applications: application Ser. No. 60/514,037 filed Oct. 24,2003, entitled “Absorbable Myocardial Lead Fixation System”, applicationSer. No. 60/514,665 filed Oct. 27, 2003, entitled “Lead ElectrodeArrangement for Myocardial Leads”, application Ser. No. 60/514,042 filedOct. 24, 2003, entitled “Tapered Tip for Myocardial Lead”, applicationSer. No. 60/514,714 filed Oct. 27, 2003, entitled “Minimally-InvasiveFixation Systems for Over-the-Tether Myocardial Leads”, application Ser.No. 60/514,039 filed Oct. 24, 2003, entitled “Distal or ProximalFixation of Over-the-Suture Myocardial Leads”, application Ser. No.60/514,146 filed Oct. 24, 2003, entitled “Myocardial Lead with FixationMechanism”, application Ser. No. 60/514,038 filed Oct. 24, 2003 entitled“Delivery Instrument for Myocardial Lead Placement” and application Ser.No. 60/514,713 filed Oct. 27, 2003, entitled “Drug-Eluting MyocardialLeads”, all of which are incorporated herein by reference.

Reference is hereby made to the following commonly assigned U.S. patentapplication Ser. No. 10/821,421, filed Apr. 9, 2004, entitled “CardiacElectrode Anchoring System” and the following commonly assigned U.S.Patent applications filed on an even date herewith, all of which areincorporated herein by reference: application Ser. No. ______, entitled“Myocardial Lead”, application Ser. No. ______ entitled “Distal orProximal Fixation of Over-the-Tether Myocardial Leads”, application Ser.No. ______, entitled “Myocardial Lead with Fixation Mechanism” andapplication Ser. No. ______, entitled “Absorbable Myocardial LeadFixation System.”

FIELD OF THE INVENTION

This invention relates generally to implantable lead assemblies forstimulating and/or sensing electrical signals in muscle tissue. Moreparticularly, it relates to myocardially implanted leads for cardiacstimulation and systems for anchoring the leads.

BACKGROUND OF THE INVENTION

Cardiac rhythm management systems are used to treat heart arrhythmias.Pacemaker systems are commonly implanted in patients to treatbradycardia (i.e., abnormally slow heart rate). A pacemaker systemincludes an implantable pulse generator and leads, which form theelectrical connection between the implantable pulse generator and theheart. An implantable cardioverter defibrillator (“ICD”) is used totreat tachycardia (i.e., abnormally rapid heart rate). An ICD alsoincludes a pulse generator and leads that deliver electrical energy tothe heart.

The leads coupling the pulse generator to the cardiac muscle arecommonly used for delivering an electrical pulse to the cardiac muscle,for sensing electrical signals produced in the cardiac muscle, or forboth delivering and sensing. The leads are susceptible to categorizationaccording to the type of connection they form with the heart. Anendocardial lead includes at least one electrode at or near its distaltip adapted to contact the endocardium (i.e., the tissue lining theinside of the heart). An epicardial lead includes at least one electrodeat or near its distal tip adapted to contact the epicardium (i.e., thetissue lining the outside of the heart). Finally, a myocardial leadincludes at least one electrode at or near its distal tip inserted intothe heart muscle or myocardium (i.e., the muscle sandwiched between theendocardium and epicardium). Some leads have multiple spaced apartdistal electrodes at differing polarities and are known as bipolar typeleads. The spacing between the electrodes can affect lead performanceand the quality of the electrical signal transmitted or sensed throughthe heart tissue.

The lead typically consists of a flexible conductor surrounded by aninsulating tube or sheath that extends from the electrode at the distalend to a connector pin at the proximal end. Endocardial leads aretypically delivered transvenously to the right atrium or ventricle andcommonly employ tines at a distal end for engaging the trabeculae.

The treatment of congestive heart failure (“CHF”), however, oftenrequires left ventricular stimulation either alone or in conjunctionwith right ventricular stimulation. For example, cardiacresynchronization therapy (“CRT”) (also commonly referred to asbiventricular pacing) is an emerging treatment for heart failure, whichrequires stimulation of both the right and the left ventricle toincrease cardiac output. Left ventricular stimulation requires placementof a lead in or on the left ventricle near the apex of the heart. Onetechnique for left ventricular lead placement is to expose the heart byway of a thoracotomy. The lead is then positioned so that one or moreelectrodes contact the epicardium or are embedded in the myocardium.Another method is to advance an epicardial lead endovenously into thecoronary sinus and then advance the lead through a lateral vein of theleft ventricle. The electrodes are positioned to contact the epicardialsurface of the left ventricle.

The left ventricle beats forcefully as it pumps oxygenated bloodthroughout the body. Repetitive beating of the heart, in combinationwith patient movement, can sometimes dislodge the lead from themyocardium. The electrodes may lose contact with the heart muscle, orspacing between electrodes may alter over time.

There is a need for an improved myocardial pacing lead suitable forchronic implantation and a minimally invasive delivery system and methodfor implanting such a lead.

SUMMARY OF THE INVENTION

The present invention, according to one embodiment, is a myocardial leadattachment system for securing a distal end of a lead within amyocardium of a patient's heart. The system includes an anchor, a tethercoupled to the anchor and a delivery instrument for receiving the anchorand advancing the anchor through a tract in the heart from a proximalentrance site to a distal exit site in such a manner that the tetherextends proximally from the anchor through the tract. The deliveryinstrument includes a needle having a distal tip and a nest positionedproximal to the distal tip that is sized to receive the anchor and anejection mechanism for ejecting the anchor from the nest.

The present invention, according to another embodiment, is a myocardiallead attachment system for securing a distal end of a lead within amyocardium of a patient's heart. The system includes an anchor having alongitudinal bore extending therethrough, a tether coupled to the anchorand a delivery instrument for receiving the anchor and advancing theanchor through a tract in the heart from a proximal entrance site to adistal exit site in such a manner that the tether extends proximallyfrom the anchor through the tract. The delivery instrument includes aneedle having a proximal end, a distal end formed with a nest forreceiving the anchor and a central lumen extending therethrough. Thedelivery instrument further includes a stylet slidably received in theneedle lumen and the anchor bore and an ejector plug formed on thestylet for engaging the anchor.

The present invention, according to another embodiment, is a method forusing a delivery instrument to implant a myocardial lead having at leasta first electrode with a delivery instrument into a heart. A myocardialanchor coupled to a tether. is mated to a distal end of the deliveryinstrument. The distal end of the delivery instrument is advancedthrough a tract in the heart. The anchor is deployed into the heart. Thedelivery instrument is withdrawn through the tract in such a manner thatthe tether extends through the tract. A myocardial lead is threaded ontothe tether. The lead is advanced over the tether into the heart.

This summary is not intended to describe each embodiment or everyimplementation of the present invention. Advantages and a more completeunderstanding of the invention will become apparent upon review of thedetailed description and claims in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a portion of the vasculature and amyocardial lead attachment system according to one embodiment of thepresent invention.

FIG. 2 is a side view of a delivery instrument for use in conjunctionwith the myocardial lead attachment system of FIG. 1 according to oneembodiment of the present invention.

FIG. 3A is a side view of a distal portion of the delivery instrument ofFIG. 2 according to one embodiment of the present invention.

FIG. 3B is a side view of the distal portion of the delivery instrumentof FIG. 2 according to another embodiment of the present invention.

FIG. 3C shows a side sectional view of the distal portion of thedelivery instrument shown in FIG. 3A.

FIG. 3D is a perspective view of the distal portion of the deliveryinstrument shown in FIG. 3A.

FIG. 4A is a sectional view of a proximal portion of the deliveryinstrument of FIG. 2 according to one embodiment of the presentinvention.

FIG. 4B is a perspective view of a distal portion of the deliveryinstrument of FIG. 2 according to one embodiment of the presentinvention.

FIG. 4C is a partial sectional view of a distal portion of the deliveryinstrument of FIG. 2 according to another embodiment of the presentinvention.

FIG. 5A is a side view of an adjustable length delivery instrument in anextended position according to one embodiment of the present invention.

FIG. 5B is a side view of the delivery instrument of FIG. 5A in aretracted position.

FIG. 6 is a sectional side view of a portion of an adjustable lengthdelivery instrument according to another embodiment of the presentinvention.

FIG. 7 is a sectional view of a distal portion of a delivery instrumentfor use in conjunction with the myocardial lead attachment system ofFIG. 1 according to one embodiment of the present invention.

FIG. 8 is a sectional view of a distal portion of a delivery instrumentfor use in conjunction with the myocardial lead attachment system ofFIG. 1 according to another embodiment of the present invention.

FIG. 9 is a sectional view of a distal portion of a delivery instrumentfor use in conjunction with the myocardial lead attachment system ofFIG. 1 according to still another embodiment of the present invention.

FIG. 10 is a sectional side view of a distal portion of a deliveryinstrument for use in conjunction with the myocardial lead attachmentsystem of FIG. 1 according to yet another embodiment of the presentinvention.

FIG. 11 is a sectional side view of a distal portion of a deliveryinstrument for use in conjunction with the myocardial lead attachmentsystem of FIG. 1 according to another embodiment of the presentinvention.

FIG. 12 is a side view of a distal portion of a delivery instrument foruse in conjunction with the myocardial lead attachment system of FIG. 1according to still another embodiment of the present invention.

FIG. 13 is a side view of a delivery instrument for use in conjunctionwith the myocardial lead attachment system of FIG. 1 according toanother embodiment of the present invention.

FIG. 14 is a side view of a delivery instrument for use in conjunctionwith the myocardial lead attachment system of FIG. 1 according toanother embodiment of the present invention.

FIG. 15A is a sectional view of the heart schematically illustrating theuse of a delivery instrument in conjunction with a myocardial leadattachment system in an epicardial-epicardial procedure according to oneembodiment of the present invention.

FIG. 15B is a sectional view of the heart schematically illustrating theuse of a delivery instrument in conjunction with a myocardial leadattachment system in an epicardial-endocardial configuration accordingto one embodiment of the present invention.

FIG. 15C is a sectional view of a portion of the heart schematicallyillustrating the use of a delivery instrument in conjunction with amyocardial lead attachment system in an intra-myocardial procedureaccording to another embodiment of the present invention.

FIG. 15D is a sectional view of a portion of the heart schematicallyillustrating the use of a delivery instrument in conjunction with amyocardial lead attachment system in a pericardial-pericardial procedureaccording to yet another embodiment of the present invention.

FIG. 16A is a sectional view of a portion of the heart and aschematically illustrated distal portion of a myocardial lead attachmentsystem having a unipolar electrode arrangement according to oneembodiment of the present invention.

FIG. 16B is a sectional view of a portion of the heart and aschematically illustrated distal portion of a myocardial lead attachmentsystem having a pseudo-unipolar electrode arrangement according to oneembodiment of the present invention.

FIG. 16C is a sectional view of a portion of the heart and aschematically illustrated distal portion of a myocardial lead attachmentsystem having a pseudo-unipolar electrode arrangement according to yetanother embodiment of the present invention.

FIG. 16D is a sectional view of a portion of the heart and aschematically illustrated distal portion of a myocardial lead attachmentsystem having a pseudo-unipolar electrode arrangement according to stillanother embodiment of the present invention.

FIG. 16E is a sectional view of a portion of the heart and aschematically illustrated distal portion of a myocardial lead attachmentsystem having a bipolar electrode arrangement according to anotherembodiment of the present invention.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

DETAILED DESCRIPTION

FIG. 1 shows a myocardial lead attachment system 10 deployed in a humanheart 12 according to one embodiment of the present invention. The heart12 includes a right atrium 14 and a right ventricle 16 separated from aleft atrium 18 and a left ventricle 20 by a septum 22. During normaloperation of the heart 12, deoxygenated blood is fed into the rightatrium 14 through the superior vena cava 24 and the inferior vena cava26. The deoxygenated blood flows from the right atrium 14 into the rightventricle 16. The deoxygenated blood is pumped from the right ventricle16 into the lungs, where the blood is re-oxygenated. From the lungs theoxygenated blood flows into the left atrium 18, then into the leftventricle 20. The left ventricle 20 beats forcefully to pump theoxygenated blood throughout the body.

The outer walls of the heart 12 are lined with a tissue known as theepicardium 28. The inner walls of the heart are lined with a tissueknown as the endocardium 30. The heart muscle, or myocardium 32, issandwiched between the endocardium 30 and the epicardium 28. A toughouter pericardial sac 33 surrounds the heart 12.

The myocardial lead attachment system 10 includes a pulse generator 34coupled to a myocardial lead 36. The pulse generator 34 is typicallyimplanted in a pocket formed, underneath the skin of the patient's chestor abdominal region. The lead 36 extends from the pulse generator 34 tothe heart 12 and is implanted in the myocardium 32 near an apex 38 ofthe heart 12. The lead 36 delivers electrical signals from the pulsegenerator 34 to an electrode located at or near a distal tip toaccomplish pacing of the heart 12 (not shown in FIG. 1). An anchormechanism 44 is coupled to the lead 36 via a tether 45 to secure thelead 36 to the heart 12 and to retain the electrode in a chosenlocation.

According to one embodiment, and generally shown in the followingfigures, the anchor mechanism 44 is an elongated T-bar, in which thetether 45 is coupled to the anchor mechanism 44 between its oppositeends and preferably at a mid-point to form the “T”. According to otherembodiments, the anchor mechanism 44 has any other shape suitable forforming an anchor against the heart 12 to retain the lead 36 in thedesired location. An important feature of the anchor mechanism 44 isthat its shape is configured to engage the heart tissue followingimplantation through a tract (not visible in FIG. 1) in the heart 12 toreduce the likelihood of re-entry of the anchor mechanism 44 into thetract. According to one embodiment, the length of the anchor mechanism44 is greater than the diameter of the tract. The “T” configuration issuch that tension exerted on the mid-point of the anchor mechanism 44via the tether 45 tends to position the anchor mechanism 44 cross-wiseover the tract, preventing the anchor mechanism from siding proximallythrough the tract. The lead 36 is then advanced over the tether 45 intothe myocardium 32. The anchor mechanism 44 resists the tensioning forceexerted on the tether 45 such that the lead 36 may be easily advancedthrough the tract.

Placement of the lead 36 and anchor mechanism 44 of FIG. 1 may beaccomplished by exposing a portion of the heart 12, for example by wayof a sternotomy, thoracotomy or mini-thoracotomy. According to otherembodiments, the heart 12 may be accessed via an endoscopic procedureaccording to known methods. Although shown implanted near the apex 38,the lead 36 may be implanted in the heart 12 anywhere pacing therapy isneeded. The anchor mechanism 44 is delivered to the heart 12 with adelivery instrument according to any of the following embodiments.

FIG. 2 shows a delivery instrument 50 according to one embodiment of thepresent invention. The delivery instrument 50 includes a needle portion58 having a distal tip 60 and a nest 62. The nest 62 is sized to receiveat least a portion of the anchor mechanism 44 (not visible in FIG. 2).The delivery instrument 50 further includes an ejection mechanism 66coupled to an actuator (not visible in FIG. 2) for ejecting the anchormechanism 44 from the nest 62.

The delivery instrument 50 includes a handle 52 having a proximal end 54and a distal end 56. The needle portion 58 is coupled to the handle 52and extends from the distal end 56. The needle portion 58 is of ahypotube construction with an internal lumen 59. The handle 52 has aninternal lumen 64 continuous with the needle lumen 59. The ejectionmechanism 66 is located on the handle 52 and is operable within theinternal lumen 64. According to other embodiments, the ejectionmechanism 66 is located elsewhere on the handle 52.

The handle 52 is sized with a length a and diameter b for easy graspingand manipulation. According to one embodiment of the present invention,a diameter b of about 5 mm provides a mechanical advantage allowingstable control over the direction of the distal needle tip 60. Further,a diameter b of about 5 mm can be used within a standard 7 mm or largerthoracic port, which is commonly used in minimally-invasivethoracoscopic procedures to access the heart 12.

An outer surface 70 of the handle 52 includes a surface feature 68.Surface feature 68 may include bumps, ribs, or bulging features on theouter surface 70 chosen to enhance the friction between the handle 58and the surgeon's hand. Surface feature 68 advantageously reducesslippage between the surgeon's hand and the handle 52 while in wet,slippery environments. The handle 52 can be made of any sterilizablemetal or polymeric material, including stainless steel, polypropylene,and polyurethane.

The shape of the distal needle portion 58 is configured to facilitateaccess to the heart 12 via thoracotomy or other procedures, such asthose mentioned above. According to one embodiment of the presentinvention, the needle portion 58 is shaped with a curved portion 72. Theshape of the curved portion 72 will be dictated in part by patientanatomy (e.g., overall heart size, peculiarities in geometry due todilation, epicardial fat, infarct, and vessels), location of thethoracotomy (posterior or anterior to an imaginary mid-axillary linebisecting the heart 12), and size of the incision into the heart tissue.According to one embodiment, the curved portion 72 has a radius ofcurvature R₇₂ of about 22 mm, a shape intended to be approximately whatthe physician would need for implanting the lead 36 via a thoracotomy.According to other embodiments, the radius of curvature R₇₂ of curvedportion 72 is from about 10 to about 35 mm (not shown). According toother embodiments, the curved portion 72 is constructed of multiplecurved segments, or is straight (not shown).

According to one embodiment, the needle portion 58 is constructed ofstainless steel. The curved portion 72 may be formed according to avariety of methods. The curved portion 72 may be formed by mechanicallybending the needle portion 58. Alternately, the needle portion 58 isheat-set so that the needle portion 58, or a smaller portion thereof, ismalleable. A chosen curvature can be imparted to the needle portion 58contemporaneous with the implantation procedure according to thesurgeon's needs.

FIG. 3A shows a portion of the needle portion 58 according to oneembodiment of the present invention. The tip 60 and nest 62 are shown aspreviously described. A distal end 60 b of the tip 60 is configured tominimize trauma to the myocardium 32 during insertion. This isaccomplished by dissecting the myocardium 32 as opposed to cutting themyocardium 32. According to one embodiment, the tip 60 is generallyconical in shape, terminating at a slightly rounded point.

FIG. 3B shows another embodiment in which the distal end 60 b of the tip60 is more rounded or blunt than the embodiment shown in FIG. 3A. Arounded or blunted tip 60 is understood to be less traumatic and lesslikely to damage coronary vessels when passing through the myocardium32. According to one embodiment, the tip 60 is generally isodiametric.An isodiametric configuration generally exerts force equally on themyocardial tissue 32 about the tip 60 when passing through tissue. Auniform force distribution reduces excessive force on the myocardialtissue 32 in directions other than along the axis of dissection.According to other embodiments, the tip 60 is provided with a sharpcutting edge.

The nest 62 is sized with a length d and a width e chosen such that thenest 62 retains the anchor mechanism 44 when the needle portion 58 isadvanced through the myocardium 32 (anchor mechanism 44 not visible inFIGS. 3A and 3B—see FIG. 3D). According to one embodiment, the nest 62is an elongated slot in the needle portion 58 opening to the needlelumen 59. The nest 62 further includes a tether slot 78 located near itsproximal end. The tether slot 78 is adapted to accept the tether 45 whenthe needle portion 58 is advanced through the myocardium 32 (See FIG.3D).

FIG. 3C shows the needle portion 58 of FIG. 3A. A proximal end 60 a ofthe tip 60 is sized with a diameter c chosen to mate with the needlelumen 59. The nest 62 includes a distal angled face or ramp 76 facingthe interior of the nest 62. The. ramp 76 is disposed at an angle θrelative to a longitudinal axis 77 of the needle 58.

FIG. 3D shows the anchor mechanism 44 received in the nest 62. Theanchor mechanism 44 is placed in the slot 62 and slid proximally intothe needle lumen 59. The tether 45 is received in the tether slot 78,permitting the anchor mechanism 44 to be slid further into the lumen 59.The ramp 76 is inclined away from the anchor mechanism 44 at the angle θat distal sliding of the anchor mechanism 44 along the axis 77 causesthe anchor mechanism 44 to ride up the ramp 76 and out of the nest 62.

FIG. 4A shows a proximal portion of the handle 52 and FIG. 4B shows adistal portion of the needle portion 58, both detailing the ejectionmechanism 66. The ejection mechanism 66 includes an elongated member 80extending from the proximal end 54 of the handle 52, through the handlelumen 64 and needle lumen 59, and terminating proximal to the nest 62. Aproximal end 82 of the elongated member 80 is operationally coupled toan actuator 84. According to one embodiment, the actuator 84 is adepressible button operable to slide the elongated member 80 distallyfrom a neutral or retracted position to an advanced position. FIG. 4Bshows the elongated member 80 in an advanced position such that a distalend 86 of the elongated member 80 has engaged the anchor mechanism 44and is pushing the anchor mechanism 44 distally within the nest 62.Doing so forces the anchor mechanism 44 to slide distally along the ramp76 and out of the nest 62.

According to one embodiment, shown in FIGS. 4A and 4B, the elongatedmember 80 is a solid tubular member sufficiently flexible to navigatethe curved portion 72 (see FIG. 2) of the needle portion 58. Accordingto another embodiment, as shown in FIG. 4C, the elongated member 80 isconstructed of a combination of a solid member 88 and a helically-woundmember 89. The solid member 88 extends through the needle lumen 59 tothe curved portion 72 and transfers axial force to the distallypositioned helical member 89, which extends through the needle lumen 59at the curved portion 72. The helical member 89 is sufficiently flexibleto navigate the curved portion 72, while the solid member 88 may berigid. According to other embodiments, the elongated member 80 is arigid member. Elongated member 80 may be constructed of a polymer ormetal.

Returning to FIG. 4A, the handle lumen 64 is formed with a ledge 90forming a mechanical stop. The ledge 90 blocks actuation of the actuator84 (i.e. further depression of the button), and preventsover-advancement of the elongated member 80. A biasing mechanism 92,including a resilient member 93, such as a spring, is interposed betweenthe actuator 84 and the handle 52. The biasing mechanism 92 biases theactuator 84 to a neutral position in which the elongated member 80 isretracted.

According to one embodiment, the ejection mechanism 66 and actuator 84are operable to advance the elongated member 80 to one of a plurality ofpre-set positions. According to another embodiment, the presentinvention is an automatic or semi-automatic delivery instrument. In thisembodiment a lever mechanism, or trigger and spring mechanism, drivesthe needle portion 58 from a retracted position into the myocardium 32in a prescribed path, ejects the anchor mechanism 44 and retracts theneedle portion 58 to its original position.

FIGS. 5A and 5B show a delivery instrument 50′ which is generallysimilar to the delivery instrument 50 shown FIG. 2. The length of theneedle portion 58′ of the instrument 50′ extending from the handle 52′is adjustable by sliding portions of the needle portion 58′ into thehandle lumen 64′. In one embodiment, needle portion 58′ is retained in achosen position within the handle lumen 64′ via a keeper mechanism, suchas a set screw 94′, extending through the handle 52′. If the physiciandesires more needle length, N, as shown in FIG. 5A, either for patientswith thick thoracic walls requiring a deeper reach to the epicardium 28or for thoracoscopic procedures, he may adjust accordingly. If herequires less length N′, as shown in FIG. 5B, the needle portion 58′ maybe retracted into the lumen 64′.

FIG. 6 shows another embodiment of the adjustable length deliveryinstrument 50′ in which the needle portion 58′ is adjustably coupled tothe handle 52′ via a collet mechanism 95′. According to one embodiment,the needle portion 58′ is provided with a sleeve 96′ having an open end96 a′ facing proximally and a distal end 96 b′ coupled to the needleportion 58′ via guide member 98′. The sleeve 96′ is sized to receive thedistal end 56′ of the handle 52′. The sleeve 96′ and the distal end 56′of the needle 52′ are provided with complementary threads 97′. Rotationof the sleeve 96′ about the handle threads 98′ advances the sleeve 96′onto the handle 52′, shortening the effective length of the needleportion 58′. Reverse rotation advances the needle portion 58′ distallyfrom the handle 52′, increasing the effective length of the needle 58′.According to other embodiments, the needle 58′ and handle 52′ may beprovided with complementary teeth or other means for providing anadjustable length coupling.

FIG. 7 shows a delivery instrument 100 for use in conjunction with themyocardial lead attachment system 10 of FIG. 1 according to anotherembodiment of the present invention. The instrument 100 includes a tubeor needle 102 having a nest 106 for receiving an anchor mechanism 108,and an ejection mechanism 109 for ejecting the anchor mechanism 108 fromthe nest 106. A proximal portion of the needle 102 may be attached to ahandle to facilitate manipulation (not shown).

According to the present embodiment, the nest 106 is an open sleeve at adistal end of the needle 102. The anchor mechanism 108 is received inthe nest 106 and protrudes outwardly from the nest 106. The needle 102includes a crimp or detent 110 near to and proximal to the nest 106 forcontacting a proximal or trailing edge 112 of the anchor mechanism 108.An inside diameter f of the nest 106 is slightly greater than an outsidediameter g of the anchor mechanism 108, such that the anchor mechanism108 can readily release from the nest 106 upon application of arelatively small force on the anchor mechanism 108 directed distallyfrom the needle 102. The anchor mechanism 108 is coupled to a tether 113as previously described. The needle 102 is further provided with acentral lumen 114 extending therethrough.

The ejection mechanism 109 is a stylet 115 coupled to an ejection plug116. The stylet 115 has a sharpened distal tip 117 shaped to effectivelydissect the tissue of the myocardium 32. According to other embodiments,the tip 117 is blunt or rounded to reduce trauma to the myocardium 32.The stylet 115 extends through the needle lumen 114 and through a bore118 extending longitudinally through the anchor mechanism 108. Theejector plug 116 is spherical and is sized and shaped smaller than aninside diameter h of the needle 102 at the crimp 110 so as to passthrough the crimp 110 but larger than an inside diameter I of the bore118 in the anchor mechanism 108 so as to contact the trailing edge 112of the anchor mechanism 108. According to other embodiments, the ejectorplug 116 has a cylindrical or other shape. According to still otherembodiments, the ejector plug 116 is not formed integrally with thestylet 115 but rather is a separate member such as a clip that isaffixed to the stylet 115.

During implantation, the anchor mechanism 108 is received in the nest106. The tip 117 of the stylet 115 extends through the bore 118 in theanchor mechanism 108 and protrudes from the bore 118. The tube 102 andthe stylet 115 are used to guide the anchor mechanism 108 through themyocardium 32. The crimp 110 contacts the trailing edge 112 of theanchor mechanism 108 to force the anchor mechanism 108 through themyocardium 32. Once the anchor mechanism 108 emerges from the myocardium32, the ejection mechanism 109 is actuated by advancing the stylet 115distally with respect to the tube 102, such that the ejection plug 116contacts the trailing end 112 of the anchor mechanism 108 and ejects theanchor mechanism 108 from the nest 106. This deploys the anchormechanism 108 on the surface of the heart 12. The needle 102 and stylet115 are then withdrawn.

According to one embodiment, the ejection mechanism 109 is coupled to anactuator as described with respect to the embodiment shown generally inFIGS. 2-6 to distally advance the stylet 106 (not shown). According toother embodiments, the ejection mechanism 109 is actuated by manuallyadvancing the stylet 115 with respect to the needle 102.

FIG. 8 shows a distal portion of delivery instrument 120 according toanother embodiment of the present invention. As shown in FIG. 8, theinstrument 120 includes many of the same components as the deliveryinstrument 100 of FIG. 7. The instrument 120 includes a tube or needle122 having a nest 123, an ejection mechanism 124 including a stylet orguide wire 126 and an anchor mechanism 128 coupled to a tether 130. Theinstrument 120 does not include a crimp or detent 110 as described withrespect to instrument 100 of FIG. 7, but instead includes a ledge 132forming an internal stop in the needle 122 proximal to the nest 123. Theledge 132 contacts a trailing edge 134 of the anchor mechanism 128 todrive the anchor 128 forward during implantation. The outer profile ofthe needle 102 is smooth and continuous.

The stylet 126 is provided with an ejector plug 136 as describedpreviously. According to the present embodiment, however, the ejectorplug 136 is cylindrical in shape. According to the embodiment shown, theanchor mechanism 128 includes an angled or tapered leading edge 138.Tapered edge 138 facilitates dissection of the myocardium 32 duringimplantation. The leading edge 138 of the anchor mechanism 128 may havea blunt or rounded profile similar to the profile of the needle tip 60described with reference to the embodiment shown in FIGS. 3A and 3B. Theinstrument 120 is used in a similar manner as described above withreference to the embodiment shown in FIG. 7.

FIG. 9 shows a sectional view of a distal portion of a stylet deliveryinstrument 140 according to another embodiment of the present invention.The instrument 140 includes many of the same components as the deliveryinstruments 100 and 120 of FIGS. 7 and 8. The instrument 140 includes atube or needle 142 having a nest 143 and an ejection mechanism 144. Theejection mechanism 144 is a stylet or guide wire 146 having an ejectorplug 145 as described previously. An anchor mechanism 148 having astepped outside diameter is received in the nest 143. A distal portion150 of the anchor mechanism 148 has a diameter j that is roughly equalto an outside diameter k of the needle 142. A proximal portion 152 ofthe anchor mechanism 148 has a diameter l slightly smaller than aninside diameter m of the needle 142, such that the anchor mechanism 148can be inserted into the nest 143. In this embodiment, a leading edge154 of the tube 142 serves to contact the anchor mechanism 148 andtransmit axial force during implantation. In this embodiment, the anchor148 may include either a blunt or a tapered leading edge 156 asdescribed previously. The instrument 140 is used in the manner describedabove with reference to FIG. 7.

FIG. 10 shows a sectional view of a distal portion of a deliveryinstrument 160 according to another embodiment of the present invention.The instrument 160 includes a stylet 162 and an anchor mechanism 164.The stylet 162 includes a distal tip 166, which is shaped for efficientdissection of the myocardium 32. A distal end 168 of the stylet 162 isprovided with a raised region 170 forming a mechanical stop. Accordingto one embodiment, a tubular sleeve 172 is positioned about the stylet162 to form the raised region 170. According to other embodiments theraised region 170 is integrally formed with the stylet 162. The anchormechanism 164, which is coupled to a tether 174, has an inner bore 176extending therethrough. An inner surface of the bore 176 includes aledge 178. A distal end 168 of the stylet 162 is received in the bore176, such that the tip 166 protrudes from the bore 176. The ledge 178 isadapted to mate with and contact the raised region 170 of the stylet 162such that upon application of an axial force on the stylet 162, theraised region 170 contacts the ledge 178 and forces the anchor mechanism164 to advance distally.

The instrument 160 is advanced through the heart 12, and the stylet 162is manipulated into the heart 12 and position the anchor mechanism 164.When the anchor mechanism 164 has been properly positioned, the stylet162 is withdrawn.

FIG. 11 shows a sectional view of a distal portion of a stylet deliveryinstrument 180 according to another embodiment of the present invention.The instrument 180 includes a stylet 182 and an anchor mechanism 184.The anchor mechanism 184 includes a blind bore 186 extending from aproximal end 188 of the anchor mechanism 184 but not all the way throughto a distal end 190. The inner surface of the blind bore 186 has adiameter sized to receive a distal end 192 of the stylet 182. As shown,the anchor 184 has a tapered leading edge 194 to facilitate dissectionof the myocardium 32. A tether 196 is attached to the anchor 184. Thestylet 182 is used to advance the anchor mechanism 184 through themyocardium 32. When the anchor mechanism 184 is located in a chosenposition, for example, on the endocardial surface 30, the stylet 182 iswithdrawn.

FIG. 12 shows a side view of a stylet delivery instrument 200 accordingto another embodiment of the present invention. The instrument 200includes a guide wire or stylet 202 and an anchor mechanism 204 coupledto a tether 206. The stylet 202 includes a tapered tip 208 shaped forefficient dissection of the myocardium 32. The anchor mechanism 204 iscoupled to a catch mechanism 210 for receiving the stylet 202. The catchmechanism 210 is a ring-shaped member and may be formed from a loopedregion of the tether 206 or formed separately and attached to the anchormechanism 204. According to one embodiment, the catch mechanism 210 isgenerally flexible. According to another embodiment, the catch mechanism210 is rigid.

The catch mechanism 210 has an inner diameter smaller than an outsidediameter n of the stylet 202, such that the stylet tip 208 can beinserted partially into the catch mechanism 210, but the stylet 202cannot fully pass through the catch mechanism 210. The stylet tip 202 isinserted into the catch mechanism .210 so that the anchor 204 liesadjacent the length of the stylet 202. According to other embodiments,the stylet 202 is provided with a circumferential groove for receivingthe catch mechanism 210 (not shown). The stylet 202 is inserted into themyocardium 32, drawing the anchor mechanism 204 along via the catchmechanism 210. Once the stylet tip 208 and the anchor mechanism 204emerge from the myocardium 32, the stylet 202 is withdrawn, disengagingfrom the catch mechanism 210. Following implantation, the catchmechanism 210 may be removed or may be left in place.

FIG. 13 shows a delivery instrument 300 in accordance with anotherembodiment of the present invention. The delivery instrument 300includes many of the features of the delivery instrument 50 shown inFIGS. 2-6. In addition, the delivery instrument 300 may be used foridentifying an appropriate or desired implant site. The deliveryinstrument 300 includes a handle 302, a needle 304, an anchor mechanism306 and an ejection mechanism 308 as previously described. According tothe present embodiment, the needle 304 is electrically conductive andextends nearly to a proximal end 310 of the handle 302. The needle 304is electrically isolated or masked via a non-conductive insulating ordielectric material polymer sleeve 311 extending the length of theneedle 304. According to one embodiment, the sleeve 311 is formed of aheat shrinkable polyimide. According to other embodiments, the sleeve311 is formed of a conformal polymer such as parylene orethylene-tetrafluoro ethylene. According to another embodiment, theneedle 304 is coated with a layer of non-conductive polymer material.

The needle 304 is electrically exposed at a distal tip 312 and at aproximal region 314. The proximal exposed region 314 is accessible via acut-out or window 316 formed in the handle 302. The needle 304 acts asan electrical conductor between the exposed proximal region 314 and theexposed distal tip 312. Alligator clips or other electrical connectorsmay be coupled to the needle 304 through the window 316 to electricallycouple the exposed distal tip 312 to a pacing and sensing analyzer forperforming sensing and pacing functions (not shown).

The exposed area at tip 312 is brought into contact with the epicardium28 or myocardium 32 to perform sensing and pacing functions prior toejection of the myocardial anchor 306. Additionally, acute therapeuticbenefit at a particular site may be assessed using said embodiment. Ifacute benefit is unacceptable, the implant site may be changed prior toimplanting the lead 36.

FIG. 14 shows a delivery instrument 400 according to another embodimentof the present invention. The delivery instrument 400 includes a handle402 coupled to a needle 404, an anchor mechanism 406 and an ejectionmechanism 408 as previously described with respect to variousembodiments. In addition, the delivery instrument 400 may be used foridentifying an appropriate or desired implant site. According to oneembodiment, this is accomplished by electrically isolating the needleregion 404 except for a small exposed or electrically active area 410 onthe conical tip 412. The needle region 404 may be electrically isolatedaccording to the techniques described with respect to the previouslydescribed embodiment shown in FIG. 13. A conductive wire 414 with aterminal end 416 in electrical communication with the electricallyactive area 410 is located in the handle 402. The wire 414 is connectedto a pacing and sensing analyzer 418. The electrically active area 410is brought into contact with the epicardium 28 or myocardium 32 toperform sensing and pacing as previously described.

The systems shown in FIGS. 2-14 are amenable to minimally-invasiveintroduction into the heart 12, such as by known thoracoscopic,mini-thoracoscopic or endoscopic techniques. In one embodiment employingan endoscopic technique, a small subxiphoid incision is made to gainvisualization of the apex 38 of the heart 12. The pericardium 33 isperforated to gain access to the epicardial surface 28. An endoscopicprobe having an open working channel is then introduced into the chest.The endoscopic probe includes common features such as a light tube,fiber optic visualization, and means to accomplish distal deflections ofthe tube or needle when formed of a malleable material as describedabove.

A target region of the heart 12 is approached and advanced sensingprobes may be used to assess the suitability of the location. Thisassessment may include typical measurements such as pacing thresholds,sensing amplitudes, and tissue impedance. These functions may beaccomplished with a delivery instrument in accordance with theembodiments shown in FIGS. 13 and 14. The working channel may also beused to assess the physiological suitability of the heart tissue.Temporary pacing of the heart 12 may also be performed at the locationthrough the working channel.

After a determination that the location is suitable for leadimplantation, an anchor mechanism 44 as is shown in FIG. 1 is advancedthrough the working channel with a delivery instrument 50 as is shown inFIGS. 2-6 in accordance with one embodiment of the present invention. Aseparate channel for fiber optic visualization may be used to assist theoperator in guiding the delivery instrument 50 through the myocardialtissue 32. In one embodiment, the visualization channel is further usedto avoid tissue structures, such as vessels, fat pads, nervous systemtissue, and infarcts.

FIGS. 15A -15D illustrate the use of the delivery instrument 50. Theneedle portion 58 of the delivery instrument 50 is used to create achannel or tract 37 through the tissue of a patient's heart 12. FIG. 15Ashows an epicardial-epicardial procedure, in which the needle portion 58is inserted in the direction shown by the arrow 99′, such that it bothenters and exits the myocardium 32 through the epicardium 28. Accordingto one embodiment, the needle tip 60 is rounded or blunt, as previouslydescribed to reduce trauma to the myocardial tissue 32 duringadvancement. During insertion through the myocardium 32, the anchormechanism 44 is located within the nest 62. A tether 45 is attached tothe anchor 44 and extends along the outside of the needle portion 58 andthe handle 52.

FIG. 15B shows an epicardial-endocardial procedure, in which the needleportion 58 travels in the path indicated by the arrow 99′, such that itenters the myocardium 32 through the epicardium 28 and exits through theendocardium 30. Again, the anchor mechanism 44 is located within thenest 62 and a tether 45 travels along the outside of the needle portion58 and handle 52.

FIG. 15C shows an intra-myocardial procedure, in which the needleportion 58 travels in the path indicated by arrow 99′, such that itenters the myocardium 32 through the epicardium 28. The anchor mechanism44 is ejected into the myocardium 32 and the delivery instrument 50 iswithdrawn. The anchor mechanism 44 remains positioned within themyocardium 32.

FIG. 15D shows a pericardial-pericardial procedure, in which the needleportion 58 travels in the path indicated by arrow 99′ such that itenters and exits through the pericardium 33 without traversing themyocardium 32.

Once the delivery instrument 50 emerges through the epicardium 28 (orthe endocardium 30, pericardium 33, or myocardium 32), the ejectionmechanism 66 is activated to dislodge the anchor mechanism 44 from thenest 62. The delivery instrument 50 is then withdrawn back through thetract 37 and removed. The tether 45 is then tensioned to cause theanchor 44 to engage against the epicardium 28 (or endocardium 30,pericardium 33 or myocardium 32).

According to other embodiments (see FIGS. 7-10C, but referring generallyto FIG. 7), a stylet or guide wire 106 in combination with a needle 102and an anchor mechanism 108 is used to create the tract 37 through themyocardium 32 for delivery of the anchor mechanism 108. Once the distalend of the needle 104 and anchor mechanism 108 have emerged through theepicardium 28 (or endocardium 30, the myocardium 32 or pericardium 33),the stylet 106 is advanced. The ejector plug 116 engages the trailingedge 112 of the anchor mechanism 108 to eject the anchor mechanism 108from the needle lumen 104. The needle 102 and stylet 106 are thenwithdrawn through the tract 37.

According to still other embodiments (see FIGS. 11 and 12, but referringgenerally to FIG. 11), a stylet or guide wire 182 in combination with ananchor mechanism 184 is used to create the tract 37 through themyocardium 32 for delivery of the anchor mechanism 184. Once the distalend 192 of the stylet or guide wire 182 and anchor mechanism 184 haveemerged through the epicardium 28 (or endocardium 30, myocardium 32 orpericardium 33) the stylet 182 is withdrawn. The anchor mechanism 184remains in place. The tether 196 is tensioned and the lead 36 advancedas described above. According to other embodiments, the stylet 182 andanchor mechanism 184 are advanced through the working channel ratherthan creating a separate tract 37.

Following delivery of the anchor mechanism 44 to the epicardial surface28 (or the myocardium 32, the endocardial surface 30 or the pericardialsurface 33) according to any of the aforementioned embodiments, thetether 45 is tensioned and the lead 36 advanced as described above.Following implantation of the myocardial lead 36, the tether 45 istensioned and secured to the myocardial lead 36 to secure the myocardiallead 36 within the myocardium 32. According to other embodiments, themyocardial lead 36 is provided with additional means to secure themyocardial lead 36 within the myocardium 32 following delivery.

The lead 36 is positioned in the heart 12 and anchored, as describedabove, to position the lead electrode 40 in chosen locations in theheart 12. Although generally shown in implanted near the apex 38, thelead 36 may be implanted anywhere in the heart pacing therapy is needed.For example, the lead 36 may be implanted in the free wall of the leftventricle 20. According to one embodiment, shown in FIG. 16A, the lead36 is configured as a unipolar lead. The electrode 40 is inserted intothe heart tissue and is an active “can.” The electrode 40 may bepositioned in the myocardium 32, as shown, or may contact the epicardium30 or the pericardium 33.

FIG. 16B shows another embodiment in which the lead 36 has twoelectrodes, a proximal anode 40 a and a distal cathode 40 b. Accordingto one embodiment, the lead 36 is implanted in a pseudo-unipolararrangement, such that the cathode 40 b is positioned within themyocardial tissue 32 and the anode 40 a is positioned on the lead body36, but not in contact with the heart tissue.

FIG. 16C shows another embodiment, in which the lead electrodearrangement is pseudo-unipolar, such that the cathode 40 b is positionedin the heart and the anode 40 a partially contacts the exteriorepicardial tissue 28 of the heart 12.

FIG. 16D shows yet another pseudo-unipolar embodiment in which thecathode 40 b is positioned in the myocardium 32 and the anode 40 a ispositioned in alignment with the outer layers of the epicardial tissue28 of the heart 12. The anode 40 a may, for example, straddle theepicardium 28 such that a portion anode 40 a is within the heart tissueand another portion is exposed to a space outside of the heart 12.

FIG. 16E shows another embodiment in which the lead 36 has a bipolararrangement wherein the cathode 40 b and anode 40 a are completelywithin the myocardial tissue 32.

In one embodiment, the cathode 40 b has an active electrode surface areaof about 1 square mm. The cathode 40 b is located near the distal tip 35of the lead body 36. An electrode spacing between the cathode 40 b andanode 40 a of more than about 2 cm would generate a unipolar lead, asdefined above. An electrode spacing of between about 1 and about 2 cmwould generate a pseudo-unipolar lead, as defined above. An electrodespacing of less than about 1 cm would generate a bipolar lead, asdefined above.

In the epicardium to epicardium configuration, the epicardium toendocardium configuration and the intramyocardial configuration, onceimplanted, the lead body 36 will serve to block the tract in themyocardium 32 created by the delivery instrument 50 and prevent furtherloss of blood from the heart 12. If it becomes necessary to repositionthe lead 36 and create a second tract, a porous, clot-promoting “plug”material can be fed over the tether 45 into the tract 37 to serve as aseal. Following implantation of the myocardial lead 36, the tether 45 istensioned and secured to the myocardial lead 36 to secure the myocardiallead 36 within the myocardium 32.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. Accordingly, the scope of the present invention is intendedto embrace all such alternative, modifications, and variations as fallwithin the scope of the claims, together with all equivalents thereof.

1. A myocardial lead attachment system for securing a distal end of alead within a myocardium of a patient's heart, the system comprising: ananchor; a tether coupled to the anchor; and a delivery instrument forreceiving and advancing the anchor through a tract in the heart from aproximal entrance site to a distal exit site in such a manner that thetether extends proximally from the anchor through the tract, saiddelivery instrument comprising: a needle having a distal tip and a nestpositioned proximal to the distal tip and sized to receive the anchor,and an ejection mechanism for ejecting the anchor from the nest.
 2. Thelead attachment system of claim 1 wherein the ejection mechanism furthercomprises an actuator for ejecting the anchor from the nest.
 3. The leadattachment system of claim 1 wherein a distal portion of the needle isformed with a radial curvature.
 4. The lead attachment system of claim 2wherein the ejection mechanism further comprises an elongated memberslidable from a retracted position to an extended position in responseto actuation of the actuator to engage the anchor mechanism.
 5. The leadattachment system of claim 4 further comprising: a mechanical stop forlimiting extension of the elongated member; and a resilient memberbiasing the actuator to retract the elongated member.
 6. The leadattachment system of claim 1 wherein the delivery instrument furthercomprises: a distal electrically active area on the needle; and aconductive member for connecting the electrically active area to anexternal electrical device.
 7. The lead attachment system of claim 1wherein the nest further includes a slot for receiving the tether. 8.The lead attachment system of claim 1 wherein the nest includes a rampadapted to assist in ejection of the anchor.
 9. The lead attachmentsystem of claim 1 further comprising a lead body having a proximal end,a distal end, and at least a first electrode near the distal end, saidlead body adapted to advance over the tether through the tract.
 10. Thelead attachment system of claim 9 wherein the lead body is a unipolarlead.
 11. The lead attachment system of claim 10 wherein the lead bodyincludes a second electrode spaced apart the first electrode apart byabout at least 2 cm.
 12. The lead attachment system of claim 9 whereinthe lead body is a pseudo-unipolar lead.
 13. The lead attachment systemof claim 9 wherein the lead body is a bipolar lead.
 14. A myocardiallead attachment system for securing a distal end of a lead within amyocardium of a patient's heart, the system comprising: an anchor havinga longitudinal bore extending therethrough; a tether coupled to theanchor; and a delivery instrument for receiving and advancing the anchorthrough a tract in the heart from a proximal entrance site to a distalexit site in such a manner that the tether extends proximally from theanchor through the tract, said delivery instrument comprising: a needlehaving a proximal end, a distal end formed with a nest for receiving theanchor and a central lumen extending therethrough; a stylet slidablyreceived in the needle lumen and the anchor bore, and an ejector plugformed on the stylet for engaging the anchor.
 15. The lead attachmentsystem of claim 14 wherein the nest is an open sleeve at the distal endof the needle.
 16. The lead attachment system of claim 15 wherein thenest has an internal stop for transmitting an axial force to the anchor.17. The lead attachment system of claim 15 wherein the anchor has aproximal region sized to be received in the nest and a distal regionsized to be retained outside of the nest.
 18. The lead attachment systemof claim 15 wherein the anchor has a tapered distal face shaped todissect the tissue of the myocardium.
 19. The lead attachment system ofclaim 14 wherein the stylet has a pointed distal end shaped to dissectthe tissue of the myocardium.
 20. A method for using a deliveryinstrument to implant a myocardial lead into the heart, said lead havingat least a first electrode, the method comprising: mating a myocardialanchor coupled to a tether to a distal end of the delivery instrument;advancing the distal end of the delivery instrument through a tract inthe heart; deploying the anchor into the heart; withdrawing the deliveryinstrument through the tract in such a manner that the tether extendsthrough the tract; threading a myocardial lead onto the tether; andadvancing the lead over the tether into the heart.
 21. The method ofclaim 20 further comprising: advancing the anchor through theepicardium, into the myocardium, and back through the epicardium; anddeploying the anchor mechanism on the epicardial surface.
 22. The methodof claim 20 further comprising: advancing the anchor through theepicardium, into the myocardium and through the endocardium; anddeploying the anchor on the endocardial surface.
 23. The method of claim20 further comprising: advancing the anchor through the epicardium andinto the myocardium; and deploying the anchor into the myocardium. 24.The method of claim 20 further comprising: advancing the anchor into thepericardium and out of the pericardium without traversing theepicardium; and deploying the anchor on the pericardial surface.
 25. Themethod of claim 20 further comprising advancing the lead body until thefirst electrode is in contact with the heart.
 26. The method of claim 20further comprising advancing the lead body until the first electrode isin contact with the myocardium.
 27. The method of claim 26 wherein thelead body includes a second electrode proximal to the first electrodeand further comprising advancing the lead body until the secondelectrode is at least partially in contact with the heart.
 28. Themethod of claim 27 further comprising advancing the lead body until thesecond electrode straddles the epicardium.
 29. The method of claim 27further comprising advancing the lead body until the second electrode isin contact with the myocardium.
 30. The method of claim 20 furthercomprising: forming a working channel and a visual channel to the heartwith an endoscopic probe; and advancing the anchor and deliveryinstrument to the heart through the working channel.